I know, I'm a walking cliche, but that's okay. After a long, long, long day of shopping and fruitless cleaning and cooking and yet more fruitless cleaning, the marshmallows were staring me down. I actually hate marshmallows, unless they are covered in graham crackers and melted chocolate, and have achieved the golden puffy runny toasted goodness.
At any rate, I wanted s'mores, and having fixed Impossible Cheeseburger Pie, only with homemade biscuit mix, I did NOT want to fire up the grill and waste the charcoal on thirty seconds worth of toasting. No, sirree, bob. That would be ridiculous.
So, I googled inside s'mores, and found that ask.com recommended heating the marshmallows on the graham cracker for four minutes at 300. I could not see this toasting the marshmallow, only melting it. The caramelization of the marshmallow is sacrosanct. It must brown. It must, or it is not a s'more, it's just marshmallow goo that ruined a perfectly good piece of chocolate. (My intense hatred of melted and not toasted marshmallow means that microwave s'mores are NOT an option.)
Here's how I did it, so the marshmallow wasn't a total loss:
Preheat oven to 300.
Line cookie sheet with foil, to minimize scraping of marshmallow goo.
Place four graham cracker halves on sheet, top with one large marshmallow.
Place in hot oven for one minute, but put 6 inches below the broiler.
After one minute, turn broiler on. Quickly break a Hershey bar in four pieces, and place one on the four other graham halves. Remove from oven when you smell toasted marshmallow.
Try to get a picture of the gorgeous, perfectly toasted marshmallow-y goodness before children descend on you like locusts.